{"title":"Three-Mediator Enhanced Collisions on an Ultramicroelectrode for Selective Identification of Single Saccharomyces cerevisiae","authors":"Yafei Chen, Yanran Liu, Dengchao Wang, Guanyue Gao* and Jinfang Zhi*, ","doi":"10.1021/acs.analchem.2c01406","DOIUrl":null,"url":null,"abstract":"<p >Selective detection of colliding entities, especially cells and microbes, is of great challenge in single-entity electrochemistry. Herein, based on the different cellular electron transport pathways between microbes and mediators, we report a three-mediator system [K<sub>3</sub>Fe(CN)<sub>6</sub>, K<sub>4</sub>Fe(CN)<sub>6</sub>, and menadione] to achieve redox activity analysis and selective identification of single <i>Saccharomyces cerevisiae</i> without the usage of antibodies. K<sub>4</sub>Fe(CN)<sub>6</sub> in the three-mediator system will oxidize near the electrode surface and increase the local concentration of K<sub>3</sub>Fe(CN)<sub>6</sub>, which will promote the redox reaction of <i>S. cerevisiae</i>. The hydrophobic mediator─menadione─can selectively penetrate through the <i>S. cerevisiae</i> membrane and get access to its intracellular redox center and can further react with K<sub>3</sub>Fe(CN)<sub>6</sub> in the bulk solution. In contrast, the mediator can only get access to the bacterial membranes of <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>, which results in different electrochemical collision signals between the above microbes. In the three-mediator system, upward step-like collision signals were observed in <i>S. cerevisiae</i> suspension, which are related to their microbial redox activity. In comparison, <i>E. coli</i> or <i>S. aureus</i> only generated downward current steps because the blockage effect of mediator diffusion suppresses their redox activities. When <i>S. cerevisiae</i> co-existed with <i>E. coli</i> or <i>S. aureus</i>, transients generated by both blockage and redox activity were observed. The approach enables us to trace the collision behaviors of different microbes and distinguish their simultaneous collisions, which is the foundation for further application of electrochemical collision technique in the specific identification of single biological entities.</p>","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":6.7000,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Analytical Chemistry","FirstCategoryId":"92","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.analchem.2c01406","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
引用次数: 2
Abstract
Selective detection of colliding entities, especially cells and microbes, is of great challenge in single-entity electrochemistry. Herein, based on the different cellular electron transport pathways between microbes and mediators, we report a three-mediator system [K3Fe(CN)6, K4Fe(CN)6, and menadione] to achieve redox activity analysis and selective identification of single Saccharomyces cerevisiae without the usage of antibodies. K4Fe(CN)6 in the three-mediator system will oxidize near the electrode surface and increase the local concentration of K3Fe(CN)6, which will promote the redox reaction of S. cerevisiae. The hydrophobic mediator─menadione─can selectively penetrate through the S. cerevisiae membrane and get access to its intracellular redox center and can further react with K3Fe(CN)6 in the bulk solution. In contrast, the mediator can only get access to the bacterial membranes of Escherichia coli and Staphylococcus aureus, which results in different electrochemical collision signals between the above microbes. In the three-mediator system, upward step-like collision signals were observed in S. cerevisiae suspension, which are related to their microbial redox activity. In comparison, E. coli or S. aureus only generated downward current steps because the blockage effect of mediator diffusion suppresses their redox activities. When S. cerevisiae co-existed with E. coli or S. aureus, transients generated by both blockage and redox activity were observed. The approach enables us to trace the collision behaviors of different microbes and distinguish their simultaneous collisions, which is the foundation for further application of electrochemical collision technique in the specific identification of single biological entities.
期刊介绍:
Analytical Chemistry, a peer-reviewed research journal, focuses on disseminating new and original knowledge across all branches of analytical chemistry. Fundamental articles may explore general principles of chemical measurement science and need not directly address existing or potential analytical methodology. They can be entirely theoretical or report experimental results. Contributions may cover various phases of analytical operations, including sampling, bioanalysis, electrochemistry, mass spectrometry, microscale and nanoscale systems, environmental analysis, separations, spectroscopy, chemical reactions and selectivity, instrumentation, imaging, surface analysis, and data processing. Papers discussing known analytical methods should present a significant, original application of the method, a notable improvement, or results on an important analyte.